The present invention relates generally to mechanisms for remote realtime viewing of an area of interest. More specifically, it relates to the use of an electronic system to aid in the alignment of a trailer hitch of a tow vehicle with the tongue of a trailer, or tow object. Still more specifically, the present invention relates to a video system to present an analog video image on a screen, where the realtime image allows a vehicle operator to view an area of interest that may include the tow vehicle hitch.
Use of a removable trailer with a vehicle involves the operations of attaching and disconnecting a tongue of the tow object with a hitch of the towing vehicle. Normally, the hitch alignment operation consists of elevating the tongue to a position higher than that of the trailer hitch, positioning the vehicle so that the hitch is positioned under the tongue, and lowering the tongue of the tow object onto the hitch in order to engage the hitch and tongue. This operation is made more difficult by the fact that the trailer hitch is usually out of view from the vehicle operator who is sitting in the cab of the vehicle, since the trailer hitch is commonly located on a bumper of the tow vehicle which is out of eye sight. Some operators, and in particular older operators, may find this operation difficult and even painful since they must rearwardly twist their necks or bodies when trying to see the tow object while manipulating the steering apparatus of the towing vehicle.
Alignment of the hitch and tongue is generally accomplished according to two methods. One method is to have a second person, or “spotter”, in place on the ground in the vicinity of the tongue of the trailer, so that he can inform the operator of the towing vehicle of the relationship of the trailer hitch to the tongue as the towing vehicle operator backs the towing vehicle into position. If ambient light is low, for reasons of evening or inclement weather, then the process is even more difficult and sometimes dangerous if a spotter is involved, since the operator may have difficulty seeing the spotter. The second method is for the towing vehicle operator to repeatedly back the towing vehicle and then exit the towing vehicle to check the alignment of the trailer hitch and the tongue.
There are a number of problems attendant with the first method. When using the first method with a spotter, both the spotter and the operator must coordinate activities so that the operator does not accidentally back the vehicle into or over the spotter. There must be close coordination between the two individuals in order to avoid injury to either personnel or equipment. Often the operator may back the vehicle too rapidly or misjudge the orientation of the hitch and tongue, despite direction from the spotter, and allow the tongue to come into contact with the rear of the towing vehicle. This may result in damage to the tow vehicle, the trailer, or both if the speed is high enough. The rear of the towing vehicle can be damaged by the tongue if the tongue is set too high, or the tow object can be damaged or knocked off of any supporting devices if it is hit by the towing vehicle. Either of these events can also injure the spotter if the spotter gets accidentally pinned between the vehicle and trailer or the trailer falls on the spotter. Damage to either the towing vehicle or the trailer is almost inevitable over a period of time.
The second method also has its problems as well. In addition to the possibility of damage to the rear of the towing vehicle, this method may be tiring, cumbersome, and time consuming for the towing vehicle operator to repeatedly exit the cab of the towing vehicle to check alignment of the tongue and hitch and then reenter the cab. Furthermore, the vehicle could inadvertently slip out of gear and move while the operator is out of the cab, thus creating a hazardous condition for both the operator and the equipment. If the operator has physical impairments or is of advanced age, then the repeated entry-exit process can be physically tiring.
Another consideration in the alignment process is the fact that many people today may own multiple vehicles, such as a sport utility vehicle (SUV), a pickup truck, and a motor home. Each type of vehicle offers different operating characteristics and must be accommodated by the towing vehicle operator when each vehicle is aligned with the same trailer.
Many electronically configured systems and methods are found in the prior art that address the problem of hitching a tow object with a towing vehicle. Otterbacher et al. (U.S. Pat. No. 6,100,795) discloses a device for locating the position of a hitch on a towing vehicle relative to the tongue of the tow object, where the device comprises a control mountable to a visor of the towing vehicle, a receiver unit attachable to the bumper of the towing vehicle and in communication with the control unit, a transmitter unit removably attachable to a trailer hitch to transmit a locating signal that is detectable by the receiver unit, and a storage case. Electronic circuitry within the control unit determines the position of the transmitter unit with relation to the receiver unit by means of the reception of the coded locating signal sent by the receiver unit. The control unit graphically displays left and right indicators to direct the towing vehicle operator to turn left or right while backing toward the tow object. It also includes an audible warning and stop indicator light for signaling when the ball hitch of the towing vehicle is positioned below the tongue of the tow object. The control unit also includes a display screen that graphically indicates the position of the towing vehicle with respect to the tow object. However, the unit does not show the nature of other objects that may be in the vicinity of the hitch area surrounding the hitch and tongue. The transmitter unit must be precisely placed, and if it inadvertently becomes dislodged, then the operator may follow incorrect directions from the control unit and damage the vehicle or the trailer. Finally, such devices may be susceptible to radio interference from external sources under some circumstances; such interference may not be easily detectable by the control unit or obvious to the operator.
Wall et al. (U.S. Pat. No. 6,480,104) discloses an arrangement of transducers positioned on the rear of a towing vehicle and on the front end (tongue side) of a trailer. A towing vehicle transceiver and a trailer transceiver are mounted on the rear of the vehicle and the front of the trailer, respectively, to sense the transducers located on the towing vehicle or trailer. The transceivers communicate with the transducers by ultrasonic signals. A control unit is located in the cab of the vehicle and communicates with the two transceivers by RF communications. The control unit receives signals from the two transceivers and, after a series of transformations that convert the signals into relative positions, displays the results on a graphical display in the cab of the vehicle. However, this disclosure assumes a permanent modification of both the vehicle and the trailer in order to install the transceivers and transducers in fixed locations, and thus portability is not a consideration; the power source is also permanently wired to the vehicle. If multiple vehicles are used for towing, then each vehicle must be similarly wired. Furthermore, the display is a graphical display rather than a video display.
Thibodeaux (U.S. Pat. No. 6,178,650) discloses a trailer hitch positioning system providing both a visual and audible notification to the vehicle operator. It comprises a pinpoint light source assembly, a light beam sensing array assembly, and a display unit. The pinpoint light source assembly is located on the trailer and is aligned with the tongue. It directs a beam to the sensing array mounted on the rear of the vehicle to activate sensors located within the array. Depending upon which sensor is activated, an indicator energized within the display unit so that the operator can determine the alignment of the tongue with relation to the ball. Communication with the display unit is made by wire rather than by wireless means, power for the unit is derived from a power adaptor connected to the cigarette lighter in the vehicle cab. The system is removable from both the vehicle and the trailer and thus portable. However, it does not provide a visual display of the hitch area, and it does contain an independent power supply.
The HindSight™ BackUp Monitor System (pat. pend.) by VizuaLogic® (TMI Products, Inc., 1493 Bentley Drive, Corona, Calif. 92879), currently marketed by a number of aftermarket retailers, comprises a video system for wide-angled viewing of the area behind a vehicle. The system interacts with the vehicle so that, when reverse gear is selected, a bumper-mounted video camera mounted in a fixed position sends a visual view of the area behind the vehicle to a monitor housed between the rear-view mirror and driver's sun visor. The camera may be permanently flush mounted either on or under the rear bumper in order to reduce notice by passers-by and thus prevent theft of the device. However, its permanent installation obviates portability considerations and multiple systems must be purchased when more than one towing vehicle is used for towing.
As can be seen, there is a need for a trailer alignment method and system capable of easily being attached and removed from a vehicle and that can be easily and universally adaptable to a wide variety of vehicle and trailer configurations. It should be simple to use, easily installed and removed without requiring permanent alteration of either the vehicle or trailer. The trailer alignment system should be usable under varying lighting conditions. It should enable a single individual to successfully align a trailer hitch with a trailer tongue without the individual leaving the cab of the truck for alignment checks. Finally, it should provide a visual, and not a graphical, depiction of the hitch alignment area so that foreign objects may be easily detected, identified, and taken into account when backing the towing vehicle.